Hi everyone,
I have been trying to build a clone of the JBL M2 reference monitors. But i have been having problems with finding a "cheep" or open source version of the JBL image control waveguide. I did read through the other posts on cloning the JBL M2 but was unable to make a waveguide that works. I plan to use the SB Audience ROSSO 65CD-T 1.4 inch compression driver as the tweeter and the Eminence Kappalite 3015LF 15 inch woofer. The box will be identical to the original because the Eminence woofer has an identical set of Thiele Small parameters. Thanks in advance for the help in designing an open source image control waveguide.
I have been trying to build a clone of the JBL M2 reference monitors. But i have been having problems with finding a "cheep" or open source version of the JBL image control waveguide. I did read through the other posts on cloning the JBL M2 but was unable to make a waveguide that works. I plan to use the SB Audience ROSSO 65CD-T 1.4 inch compression driver as the tweeter and the Eminence Kappalite 3015LF 15 inch woofer. The box will be identical to the original because the Eminence woofer has an identical set of Thiele Small parameters. Thanks in advance for the help in designing an open source image control waveguide.
Hi and welcome, you will find lots of threads and posts about waveguides here!
Use the search function or google wg+diyaudio or just browse through the "multiway" forum.
Use the search function or google wg+diyaudio or just browse through the "multiway" forum.
I have searched through the other post and was unable to get a sense of how to design this specific type of waveguide. But thanks for your input.
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It's not exactly public knowledge.. but member Patrick Bateman has taken an interest. You might look at some of his threads.
I have read his threads and was able to find a design for the BMS 4526HE compression driver but the driver is not up to the standards i am building this for. So i have massaged him about how to adapt it to work with the ROSSO 65CDN-T.
Different drivers can work since the waveguide is the main factor in the result. This of course is provided you get the right exit size, a usable exit angle and you equalise as required.
Do you think it is possible to make an adapter from 1.4 (the rosso) to 0.63 inches for the BMS without a loss in quality?
You could, and it would probably sound OK. Many would say that it's less than optimal. I guess it depends on how much work you put into it keeping things together, and how much the waveguide tends to reflect.
I would design a waveguide for 1.4 If that's not possible I'd consider removing some of the throat from the existing waveguide. Since that probably affects the way it was designed to work, you don't have much choice.
I'd have to look at the problem in detail. Perhaps a phase plug extension would be the preferred way to do that. Most people would use conical sections.
I'd have to look at the problem in detail. Perhaps a phase plug extension would be the preferred way to do that. Most people would use conical sections.
You can estimate from the price tag for the m2 how much research and development went into it. Unfortunately (or fortunately) it's not that straightforward. But I would encourage you to read through some waveguide related threads to get an understanding of what is going on.
It can be very much fun digging deeper!
If you're not intimidated by huge amounts of text, here is a
very good thread:
https://www.diyaudio.com/community/...he-easy-way-ath4.338806/page-767#post-7740409
Designing an adapter with the utmost care would cost more in time than the cost of a better set of tweeters.
An option is to create a simple conical adapter. Hornresp has a tool for this. Hornresp also has a dedicated thread where you could work through it - https://www.diyaudio.com/community/threads/hornresp.119854/unread
An option is to create a simple conical adapter. Hornresp has a tool for this. Hornresp also has a dedicated thread where you could work through it - https://www.diyaudio.com/community/threads/hornresp.119854/unread
Dose anyone have a guess as to how low the horn by Patrick Bateman is loading down to? I want to put a drive in that can crossover as low as 800 hz.
Since it is almost impossible to recreate the JBL horn what off the shelf horn do you think will be almost identical?
Off the shelf is typically pro gear and the horns don't relate well to domestic use. Try to find something that's large and more conical than exponential. Try to find something that doesn't have a narrow/short vertical but is closer to the same all around.
You want to look at "Econowave" threads if you're going to limit yourself to off the shelf horns.
You want to look at "Econowave" threads if you're going to limit yourself to off the shelf horns.